The stars of the Big Dipper have led a runaway slave family to Deacon Fuller's house, a stop on the underground railroad. Will Tommy Fuller be able to hide the runaways from a search party -- or will the secret passengers be discovered and their hope for freedom destroyed?

Tommy Fuller accidentally discovers that his family's house is a stop on the Underground Railroad when he finds a family of runaway slaves hiding in the barn. Now that he knows, can Tommy be trusted to help his father transport the slaves in the hay wagon to the next safe haven?